A composite blade is formed by laying up composite layers in which reinforced fibers are impregnated with resin. The composite layers are laid up in a blade thickness direction that is a direction connecting a suction side and a pressure side of the composite blade. The composite blade includes a thick part that has a surface layer area from a surface of the thick part to a predetermined depth in the blade thickness direction and a deep layer area at a depth larger than the predetermined depth from the surface in the blade thickness direction. A median value in a predetermined range of thicknesses of each composite layer in the surface layer area is smaller than a median value in a predetermined range of thicknesses of each composite layer in the deep layer area.